NEW YORK -- New York City officials say they have pinpointed the source of the Legionnaires' disease outbreak in the South Bronx that left 12 people dead and sickened more than 100, CBS New York reports.
A contaminated rooftop air-conditioning unit at the historic Opera House Hotel was to blame for the biggest outbreak of the disease in the city's history, Dr. Mary Bassett, the city health commissioner, said Thursday.
After extensive sampling and testing for the bacteria that causes Legionnaires' disease, laboratories have matched the strain found in the hotel's rooftop unit - also called a cooling tower - with the strain found in 25 patients, some of whom died, Bassett said.
"The outbreak is over," Bassett said, noting the maximum incubation period has passed since the last new report of someone coming down with symptoms.
Dr. Jay K. Varma, a deputy health commissioner for disease control, said health officials investigating the outbreak learned nine days into their probe, on July 29, that a guest who had stayed at the hotel had become ill.
"We eliminated the danger posed by the Opera House Hotel's cooling tower as soon as it tested positive for disease-causing Legionella," Bassett said in a news release. "Today, all cooling towers in the affected area have been disinfected, and all cooling towers across the City are being evaluated and disinfected if necessary."
In all, there have been 128 cases and almost all patients hospitalized with the disease have been discharged, officials said.
Cooling towers in 18 buildings tested positive for the bacteria, and the outbreak prompted city and state officials to require the testing and inspection of building cooling towers across the state. Mist of warm water from the towers can spread bacteria and cause illness if inhaled.
The outbreak has become the city's most significant public health crisis since last fall's Ebola scare. For more than a month, cases of Legionnaires' - a form of pneumonia especially dangerous for the elderly and for people with underlying health issues - have been reported throughout a section of the South Bronx, the city's poorest neighborhood.
After speculation last week on the source of the outbreak, the Opera House Hotel said that its 2-year-old cooling tower has been cleaned routinely and that managers acted quickly to get it cleaned again after learning of the Legionnaires' problem.
"We did not wait for test results; we acted quickly," Glenn Isaacs, vice president of owner Empire Hotel Group, said in a statement at the time.
The Opera House Hotel's building is more than a century old and once housed performances by Harry Houdini, the Marx Brothers and George Burns. It's in the heart of the South Bronx.
On Tuesday, Mayor Bill de Blasio signed new legislation aimed at regulating cooling towers in response to the outbreak.
The new law requires landlords to register, inspect and regularly clean cooling towers. Building owners would also need to get an annual certification. Those who do not comply would face fines up to $25,000.